Page 1 - dust collection systems

Gas-solid separation devices associated with pneumatic
conveying systems have two functions. To recover the

conveyed material as much as possible and to minimize

pollution of the environment by the working material.

Different separation mechanisms used based on the size of

particles are: gravity settling chambers, cyclone separators

and bag type fabric filters.

If a bulk material consists of relatively large and heavy

particles, with no fine dust, it may be possible to collect the

material in a simple bin, where the solid material falls under

gravity to the bottom of the bin while the gas is taken off

through a suitable vent.

However, if a bulk material is of slightly smaller particle size,

it may be required to enhance the gravitational effect. The

most common method for this is to impart spin to the gas-

solid stream so that the solid particles are thrown outwards

while the gas is drawn off from the centre of the vortex. A

cyclone separator works on this principle.

If particles are fine and especially if they are also of low

density, separation in a cyclone may not be fully effective,

and in this case the gas-solid stream may be vented through

a fabric filter.